I've done it that way for many years. A visit to local post office. A few photocopies, EMS tracked postage, all up about 80 Baht, and takes 10-15 minutes. Sure beats going to CW, and no worries about online not being accepted. Best way for me
The 180 days is nothing to do with taxation. 180 is merely the length of the permission to stay stamp. A person can leave after 30 days if they so wish
Anonymous participant 245 Taxation in Thailand for people without a work permit are based solely on remittances and nothing to do with earnings overseas